Ideas from 'works' by Gottfried Leibniz [1690], by Theme Structure

green numbers give full details    |     back to texts     |     unexpand these ideas


1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
Leibniz aims to give coherent rational support for empiricism
                        Full Idea: Leibniz's philosophy largely serves to justify and enable a coherent empirical account of the world.
                        From: Gottfried Leibniz (works [1690]), quoted by Franklin Perkins - Leibniz: Guide for the Perplexed 4.I
                        A reaction: A nice counter to the simplistic idea of Locke as empiricist and Leibniz as rationalist. Leibniz is explicit that science needs a separate 'metaphysics' to underpin it. Perkins says Locke constructs experience, and Leibniz analyses it.
1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Metaphysics is a science of the intelligible nature of being
                        Full Idea: For Leibniz, metaphysics is above all a science of the intelligible nature of being.
                        From: report of Gottfried Leibniz (works [1690]) by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 4.3.1
                        A reaction: [Their footnote gives two quotes in support] I could take this as my motto. We are not studying the 'nature of being', because we can't. We are studying what is 'intelligible' about it; my thesis is that the need for intelligibility imposes an order.
1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science
Leibniz tried to combine mechanistic physics with scholastic metaphysics
                        Full Idea: Leibniz made a sustained attempt to combine a mechanistic physics with something like a scholastic metaphysics.
                        From: report of Gottfried Leibniz (works [1690]) by Robert Pasnau - Metaphysical Themes 1274-1671 20.1
                        A reaction: This seems to me clear enough, and a lot of current philosophers seem to underestimate how Aristotelian Leibniz was.
2. Reason / A. Nature of Reason / 1. On Reason
Reason is the faculty for grasping apriori necessary truths
                        Full Idea: Leibniz actually characterises reason as the faculty for apprehending priori, necessary truths.
                        From: report of Gottfried Leibniz (works [1690]) by Tyler Burge - Frege on Apriority (with ps) 2
                        A reaction: No wonder it is called the Age of Reason when the claims are this grandiose.
2. Reason / A. Nature of Reason / 4. Aims of Reason
For Leibniz rationality is based on non-contradiction and the principle of sufficient reason
                        Full Idea: Leibniz distinguished two fundamental principles of rationality - the principle of non-contradiction and the principle of sufficient reason.
                        From: report of Gottfried Leibniz (works [1690]) by José A. Benardete - Metaphysics: the logical approach Ch.18
2. Reason / B. Laws of Thought / 2. Sufficient Reason
Leibniz said the principle of sufficient reason is synthetic a priori, since its denial is not illogical
                        Full Idea: Leibniz assigns synthetic a priori status to the principle of sufficient reason, readily conceding that one can deny it without fear of inconsistency.
                        From: report of Gottfried Leibniz (works [1690]) by José A. Benardete - Metaphysics: the logical approach Ch.18
2. Reason / E. Argument / 6. Conclusive Proof
Leibniz is inclined to regard all truths as provable
                        Full Idea: Leibniz has an inclination to regard all truths as provable.
                        From: report of Gottfried Leibniz (works [1690]) by Gottlob Frege - Grundlagen der Arithmetik (Foundations) §15
                        A reaction: Leibniz sounds like the epitome of Enlightenment optimism about the powers of reason. Could God prove every truth? It's a nice thought.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
Number cannot be defined as addition of ones, since that needs the number; it is a single act of abstraction
                        Full Idea: Leibniz's talk of the addition of ones cannot define number, since it cannot be specified how often they are added without using the number itself. Number must be an organic unity of ones, achieved by a single act of abstraction.
                        From: Gottfried Leibniz (works [1690]), quoted by Kit Fine - Cantorian Abstraction: Recon. and Defence §1
                        A reaction: I doubt whether 'abstraction' is the right word for this part of the process. It seems more like a 'gestalt'. The first point is clearly right, that it is the wrong way round if you try to define number by means of addition.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / j. Infinite divisibility
The continuum is not divided like sand, but folded like paper
                        Full Idea: Leibniz said the division of the continuum should not be conceived 'to be like the division of sand into grains, but like that of a tunic or a sheet of paper into folds'.
                        From: report of Gottfried Leibniz (works [1690], A VI iii 555) by Richard T.W. Arthur - Leibniz
                        A reaction: This from the man who invented calculus. This thought might apply well to the modern physicist's concept of a 'field'.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals
A tangent is a line connecting two points on a curve that are infinitely close together
                        Full Idea: We have only to keep in mind that to find a tangent means to draw a line that connects two points of a curve at an infinitely small distance.
                        From: Gottfried Leibniz (works [1690]), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.1
                        A reaction: [The quote can be tracked through Kitcher's footnote]
Nature uses the infinite everywhere
                        Full Idea: Nature uses the infinite in everything it does.
                        From: Gottfried Leibniz (works [1690]), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.1
                        A reaction: [The quote can be tracked through Kitcher's footnote] He seems to have had in mind the infinitely small.
7. Existence / C. Structure of Existence / 6. Fundamentals / c. Monads
Leibniz proposes monads, since there must be basic things, which are immaterial in order to have unity
                        Full Idea: Leibniz believes in monads because it would be contrary to reason or divine wisdom if everything was compounds, down to infinity; there must be ultimate unified building-blocks; they cannot be material, for material things lack genuine unity.
                        From: report of Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Ch.3
                        A reaction: It is hard to discern the basis for the claim that only immaterial things can have unity. The Greeks proposed atoms, and we have no reason to think that electrons lack unity.
8. Modes of Existence / A. Relations / 1. Nature of Relations
If relations can be reduced to, or supervene on, monadic properties of relata, they are not real
                        Full Idea: Leibniz argued that relations could be reduced to monadic properties and so were dispensable, and some still agree, saying relations supervene on monadic properties of the relata, and are not actually real.
                        From: report of Gottfried Leibniz (works [1690]) by Chris Swoyer - Properties 7.4
                        A reaction: At the very least a background of space and/or time seem required, in addition to any properties the relata may have. y only becomes 'to the left of x' when x appears to its right, so the relation doesn't seem to be intrinsic to y.
Relations aren't in any monad, so they are distributed, so they are not real
                        Full Idea: The relations which connect two monads are not in either the one or the other, but equally in both at once; and therefore properly speaking, in neither. I do not think you would wish to posit an accident which would inhere simultaneously in two subjects.
                        From: Gottfried Leibniz (works [1690], G II:517), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 2.4.3
                        A reaction: Where Russell affirms relations as universals, and scholastics make them properties of individuals, Leibniz denies their reality entirely. It seems obvious that once the objects and properties are there, the relations come for free.
8. Modes of Existence / C. Powers and Dispositions / 4. Powers as Essence
Forms have sensation and appetite, the latter being the ability to act on other bodies
                        Full Idea: Leibniz's form contains both sensation and appetite, and he seems to associate appetite with the ability a body has to act on another.
                        From: report of Gottfried Leibniz (works [1690]) by Daniel Garber - Leibniz:Body,Substance,Monad 3
                        A reaction: It strikes me (you may be surprised to hear) that this concept is not unlike Nietzsche's all-mastering 'will to power'. I offer Idea 7140 in evidence.
The essence of a thing is its real possibilities
                        Full Idea: In Leibniz's view, the essence of a thing is fundamentally the real possibilities of that thing.
                        From: report of Gottfried Leibniz (works [1690]) by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 4.3.3
                        A reaction: Note that the essences are individual. On the whole I would prefer Leibniz in his own words, but this is too good to lose (..but see Idea 12981). It is the aspect of Leibniz that fits perfectly with modern scientific essentialism.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Leibniz moved from individuation by whole entity to individuation by substantial form
                        Full Idea: By 1680 Leibniz had clearly abandoned the 'whole entity' conception of individuation, for a conception grounded in substantial form alone.
                        From: report of Gottfried Leibniz (works [1690]) by Daniel Garber - Leibniz:Body,Substance,Monad 2
                        A reaction: In other words, Leibniz became more of an Aristotelian, and more of an essentialist.
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
The laws-of-the-series plays a haecceitist role
                        Full Idea: Leibniz takes the laws-of-the-series to play a haecceitistic role.
                        From: report of Gottfried Leibniz (works [1690]) by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 7.5
                        A reaction: Idea 13092 for law-in-the-series. He thinks that a law-in-a-series is unique to a substance, and so can individuate it. That is a pretty good proposal, if anything is going to do the job. Perhaps I do believe in haecceities, as unique bundles of powers?
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
Identity of a substance is the law of its persistence
                        Full Idea: For there to be a certain persisting law which involves the future states of that which we conceive as one and the same continuant, this is what I say constitute's a substance's identity.
                        From: Gottfried Leibniz (works [1690], G II:264), quoted by David Wiggins - Sameness and Substance 3.1
                        A reaction: This is a key remark for those who thing 'persistence conditions' are basic to metaphysics. I'm not so sure.
9. Objects / B. Unity of Objects / 1. Unifying an Object / c. Unity as conceptual
Leibniz bases pure primitive entities on conjunctions of qualitative properties
                        Full Idea: Leibniz is committed with apparent consistency to both a purely qualitative character of all thisnesses, and to primitiveness of individual identity. He regards thisnesses as conjunctions of simpler, logically independent suchnesses.
                        From: report of Gottfried Leibniz (works [1690]) by Robert Merrihew Adams - Primitive Thisness and Primitive Identity 5
                        A reaction: Hence Leibniz is held to say that all of the qualitative properties are 'essential' to the object, since all of them are needed to constitute its identity. Hence absolutely nothing about an object, even an electron, could be different, which is daft.
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
Substances are essentially active
                        Full Idea: For Leibniz, it is the very essence of substances to be sources of activity.
                        From: report of Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Ch.2
                        A reaction: This makes the views of Leibniz sympathetic to modern essentialism (of which I am a fan), because it places active power at the centre of what it is to exist, rather than action being imposed on matter which is otherwise passive.
Leibnizian substances add concept, law, force, form and soul
                        Full Idea: To the traditional idea of substance (independent, subjects of predication, active, persistent) Leibniz adds, distinctively, complete individual concept, law-of-the-series, active force, form and soul or entelechy.
                        From: report of Gottfried Leibniz (works [1690]) by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 6.1.1
                        A reaction: 'Form' seems to be Aristotelian, and 'soul' seems ridiculous. I don't think the 'complete concept' is much help. However, the 'law-in-the-series' is very interesting (Idea 13079), if employed sensibly, and 'active force' is spot-on. Powers define reality.
9. Objects / C. Structure of Objects / 2. Hylomorphism / c. Form as causal
Leibniz strengthened hylomorphism by connecting it to force in physics
                        Full Idea: A standard criticism of the scholastic notions of matter and form is that they are obscure and unintelligible. But in Leibniz's system they are connected directly with notions of active and passive force that play an intelligible roles in his physics.
                        From: report of Gottfried Leibniz (works [1690]) by Daniel Garber - Leibniz:Body,Substance,Monad 4
                        A reaction: This seems to me to be very appealing. Aristotle was clearly on the right lines, but just ran out of things to say, once he had pointed in the right direction. Maybe 'fields' and 'strings' can fill out the Aristotelian conception of form.
9. Objects / D. Essence of Objects / 9. Essence and Properties
Leibniz's view (that all properties are essential) is extreme essentialism, not its denial
                        Full Idea: The view standardly attributed to Leibniz, that makes all an individual's properties essential to it should be regarded as an extreme version of essentialism, not a denial of essentialism.
                        From: report of Gottfried Leibniz (works [1690]) by Penelope Mackie - How Things Might Have Been 1.1
                        A reaction: Wiggins disagrees, saying that Leibniz was not an essentialist, which is an interesting topic of research for those who are interested. I would take Leibniz to be not an essentialist, on that basis, as essentialism makes a distinction. See Quine on that.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Leibniz was not an essentialist
                        Full Idea: Leibniz was not an essentialist.
                        From: report of Gottfried Leibniz (works [1690]) by David Wiggins - Sameness and Substance Renewed 4.2 n4
                        A reaction: Assuming this is right, it is rather helpful, because you can read mountains of Leibniz without ever being quite sure. Mackie says he IS an extreme essentialist, treating all properties as essential. Wiggins makes more sense there.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
Two eggs can't be identical, because the same truths can't apply to both of them
                        Full Idea: It isn't possible to have two particulars that are similar in all respects - for example two eggs - for it is necessary that some things can be said about one of them that cannot be said about the other, else they could be substituted for one another.
                        From: Gottfried Leibniz (works [1690]), quoted by David Wiggins - Sameness and Substance 2.2
                        A reaction: [from a 'fragment' for which Wiggins gives a reference] This quotation doesn't rest the distinctness of the eggs on some intrinsic difference, but on the fact that we can say different things about the two eggs.
9. Objects / F. Identity among Objects / 9. Sameness
Things are the same if one can be substituted for the other without loss of truth
                        Full Idea: Leibniz's definition is as follows: Things are the same as each other, of which one can be substituted for the other without loss of truth ('salva veritate').
                        From: Gottfried Leibniz (works [1690]), quoted by Gottlob Frege - Grundlagen der Arithmetik (Foundations) §65
                        A reaction: Frege doesn't give a reference. (Anyone know it?). This famous definition is impressive, but has problems when the items being substituted appear in contexts of belief. 'Oedipus believes Jocasta (his mother!) would make a good wife'.
10. Modality / A. Necessity / 2. Nature of Necessity
Necessary truths are those provable from identities by pure logic in finite steps
                        Full Idea: Leibniz argued that the necessary truths are just those which can be proved from identities by pure logic in a finite number of steps. ...[232] this claim is vindicated by Gentzen's sequent calculus.
                        From: report of Gottfried Leibniz (works [1690]) by Ian Hacking - What is Logic? §01
                        A reaction: This seems an odd idea, as if there were no necessary truths other than those for which a proof could be constructed. Sounds like intuitionism.
10. Modality / B. Possibility / 1. Possibility
How can things be incompatible, if all positive terms seem to be compatible?
                        Full Idea: It is yet unknown to me what is the reason of the incompossibility of things, or how it is that different essences can be opposed to each other, seeing that all purely positive terms seem to be compatible.
                        From: Gottfried Leibniz (works [1690], G VII:194), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 3.4.4
                        A reaction: Since 'heavy' seems straightforwardly opposed to 'light', we would have to ask what he means by 'positive'. The suspicion is that all things are compossible by definition, so it is not surprising that impossibilities are a bit puzzling.
10. Modality / B. Possibility / 5. Contingency
A reason must be given why contingent beings should exist rather than not exist
                        Full Idea: A reason must be given why contingent beings should exist rather than not exist.
                        From: Gottfried Leibniz (works [1690])
                        A reaction: Spinoza rejects all contingency, but this seems an interesting support for it, even though we may need a reason for something where God does not because it is self-evident.
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Leibniz narrows down God's options to one, by non-contradiction, sufficient reason, indiscernibles, compossibility
                        Full Idea: Leibniz sets up increasingly stringent conditions possible worlds must meet. The weakest is non-contradiction, for truths of reason; then sufficient reason, for rational worlds; then identity of indiscernibles, for duplicates; then compossibility.
                        From: report of Gottfried Leibniz (works [1690]) by Rom Harré - Laws of Nature 4
                        A reaction: [my summary of a very nice two pages by Harré] God is the source of the principles which do the narrowing down.
Each monad expresses all its compatible monads; a possible world is the resulting equivalence class
                        Full Idea: Leibniz argued that each monad mirrors or expresses every monad with which it is compossible. Hence compossibility is an equivalence relation among monads; possible worlds may then be identified as the corresponding equivalence classes.
                        From: report of Gottfried Leibniz (works [1690]) by Ian Rumfitt - The Boundary Stones of Thought 6.1
                        A reaction: [Rumfitt cites Benson Mates 1986:IV.1 for this claim] There is an analogous world of all the human minds that are in communication with one another - something like a 'culture'.
Leibniz proposed possible worlds, because they might be evil, where God would not create evil things
                        Full Idea: In his early writings the principle of sufficient reason made it difficult for Leibniz to conceive of possible things;...raising this to possible worlds means God does not choose things that are evil, but chooses a world which must have evil in it.
                        From: report of Gottfried Leibniz (works [1690]) by Matthew Stewart - The Courtier and the Heretic Ch.14
                        A reaction: Where we think of possible worlds as explanations for conditional and counterfactual truths (I take it), Leibniz developed the original idea as part of his huge effort to achieve a consistent theodicy.
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Leibniz has a counterpart view of de re counterfactuals
                        Full Idea: When Leibniz has the grounds of de re counterfactuals in mind, a counterpart picture, we have argued, is at work.
                        From: report of Gottfried Leibniz (works [1690]) by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 3.2.2
                        A reaction: If Leibniz were a 'superessentialist', then individuals would be totally worldbound (because their relations would be essential). Cover/Hawthorne argue that he is just a 'strong' essentialist, allowing possible counterparts. Quite persuasive.
11. Knowledge Aims / A. Knowledge / 2. Understanding
For Leibniz, divine understanding grasps every conceivable possibility
                        Full Idea: For Leibniz, what is this understanding which God has? What does it contain? All possibilities in all possible combinations, that is, everything which can be conceived.
                        From: report of Gottfried Leibniz (works [1690]) by Franklin Perkins - Leibniz: Guide for the Perplexed 2.III
                        A reaction: I like this, because it strikes me as essential that understanding should embrace possibilities as well as actualities. Perkins points out that the possibilities are restricted by an awareness of the limitations imposed by combination.
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
Leibniz said dualism of mind and body is illusion, and there is only mind
                        Full Idea: Leibniz held that dualism of mind and body is an illusion and that both are really the same thing, and that this thing is mind.
                        From: report of Gottfried Leibniz (works [1690]) by R Martin / J Barresi - Introduction to 'Personal Identity' p.22
                        A reaction: I am puzzled by this, as Leibniz is famous for the view that mind and body are parallel. See idea 5038, and also 2109 and 2596. Monads are, of course, entirely mental, and are the building blocks of reality. Clearly I (and you) must read more Leibniz.
Leibniz is an idealist insofar as the basic components of his universe are all mental
                        Full Idea: To say that Leibniz is an idealist is to say that simple substances, the basic building-blocks of the universe, are all mental or at least quasi-mental in nature
                        From: report of Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Ch.3
                        A reaction: This is a bit different from the Berkelian type of idealism, which says that reality consists entirely of events within thinking minds. Is a monad the thinker or the thought?
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
The essence of substance is the law of its changes, as in the series of numbers
                        Full Idea: The essence of substance consists in ...the law of the sequence of changes, as in the nature of the series in numbers.
                        From: Gottfried Leibniz (works [1690], A 6.3.326), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 6.1.2
                        A reaction: Thus we might say, in this spirit, that the essence of number is the successor operation, as defined by Dedekind and Peano (and perhaps their amenability to inductive proof). I like this. Metaphysicians rule - they penetrate the heart of nature.
15. Nature of Minds / B. Features of Minds / 1. Consciousness / a. Consciousness
Leibniz introduced the idea of degrees of consciousness, essential for his monads
                        Full Idea: The designation of degrees of conscious awareness is one of Leibniz's most significant innovations, and it is fundamental to almost every aspect of his account of monads.
                        From: report of Gottfried Leibniz (works [1690]) by Franklin Perkins - Leibniz: Guide for the Perplexed 4.I
                        A reaction: A very important development, which seems to have been ignored by philosophers for three hundred years, since they usually treat consciousness as all-or-nothing. Introspection makes degrees obvious, and I suspect sparrows are down the scale.
16. Persons / F. Free Will / 6. Determinism / a. Determinism
We think we are free because the causes of the will are unknown; determinism is a false problem
                        Full Idea: The will has its causes, but since we are ignorant of them, we believe ourselves independent. It is this chimera of imaginary independence which revolts us against determinism, and which brings us to believe there are difficulties where there are none.
                        From: Gottfried Leibniz (works [1690]), quoted by Matthew Stewart - The Courtier and the Heretic Ch.16
                        A reaction: It seems that in his notebooks Leibniz was actually a (Spinozan) determinist. So he should have been, given his view that we live in the best of all possible worlds, and his claim that mind and brain run like two clocks. (Ideas 2114 and 2596)
17. Mind and Body / A. Mind-Body Dualism / 3. Panpsychism
Leibniz has a panpsychist view that physical points are spiritual
                        Full Idea: In Leibniz's panpsychism, the so-called 'physical' points are souls or spiritual 'monads'.
                        From: report of Gottfried Leibniz (works [1690]) by R Martin / J Barresi - Introduction to 'Personal Identity' p.23
                        A reaction: I'm not convinced that 'panpsychism' is the right description for Leibniz's theory of monads. I take panpsychism to be either a dualist or a dual aspect (or property dualism) view. Leibniz seems to believe there is strictly one substance.
17. Mind and Body / A. Mind-Body Dualism / 4. Occasionalism
Occasionalism give a false view of natural laws, miracles, and substances
                        Full Idea: Leibniz's three objections to occasionalism are: it disturbs the concept of laws of nature used in physics; it introduces perpetual miracles; and it doesn't recognise activity of substances (leading to the Spinozan heresy that God is the only substance).
                        From: report of Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Ch.2
                        A reaction: I wonder what would happen if, within the viewpoint of occasionalism, God suddenly packed up and abandoned his job? Presumably the world wouldn't disappear, so there would still be substances, but passive ones, in chaos.
18. Thought / D. Concepts / 2. Origin of Concepts / a. Origin of concepts
Concepts are ordered, and show eternal possibilities, deriving from God
                        Full Idea: Leibniz understood concepts as corresponding to eternal possibilities, with both concepts and their ordering having their foundation in the divine mind.
                        From: report of Gottfried Leibniz (works [1690]) by Richard T.W. Arthur - Leibniz 2 'Nominalism'
                        A reaction: It is is no longer the fashion to think of concepts as 'ordered', and yet there is a multitude of dependence relations between them.
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
Leibniz was the first modern to focus on sentence-sized units (where empiricists preferred word-size)
                        Full Idea: Leibniz seems to be the first modern philosopher to focus on sentence-sized units that he called propositions. The Empiricists among the moderns focused on word-sized units like ideas.
                        From: report of Gottfried Leibniz (works [1690]) by William D. Hart - The Evolution of Logic 2
                        A reaction: Historically, the sentential logic of the Stoics has a claim to have started this one. I find my initial sympathies to be with the empiricists.
20. Action / B. Preliminaries of Action / 2. Willed Action / d. Weakness of will
Limited awareness leads to bad choices, and unconscious awareness makes us choose the bad
                        Full Idea: For Leibniz, while the limits of our knowledge explain why we sometimes choose things we think are good but which turn out to be bad, the force of minute perceptions explains why we sometimes choose things that we know are bad.
                        From: report of Gottfried Leibniz (works [1690]) by Franklin Perkins - Leibniz: Guide for the Perplexed 4.IV
                        A reaction: To be overwhelmed by selfish greed doesn't sound like a 'minute perception'. Leibniz thinks all desires are reactions to perceptions. Observing our degrees of knowledge is an interesting response to the intellectualist view of weakness of will.
21. Aesthetics / A. Aesthetic Experience / 4. Beauty
Leibniz identified beauty with intellectual perfection
                        Full Idea: Leibniz identified beauty with intellectual perfection.
                        From: report of Gottfried Leibniz (works [1690]) by Sebastian Gardner - Aesthetics 1.2.1
                        A reaction: Well he would, wouldn't he? Swots like Leibniz are inclined to value things which only they can fully appreciate. There may be intellectual subject matter in the study of a rose, but I do not believe that it is needed to appreciate the beauty.
22. Metaethics / C. Ethics Foundations / 1. Nature of Ethics / g. Moral responsibility
Humans are moral, and capable of reward and punishment, because of memory and self-consciousness
                        Full Idea: For Leibniz, it is by virtue of possessing memory and self-consciousness that human minds are moral beings, capable of reward and punishment.
                        From: report of Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Ch.4
                        A reaction: I like this because it makes no mention of free will (though Leibniz struggled to defend free will). I would add meta-thought (the ability to ponder and evaluate our own thinking), which makes a change of mind possible.
25. Social Practice / D. Justice / 2. The Law / c. Natural law
Natural law theory is found in Aquinas, in Leibniz, and at the Nuremberg trials
                        Full Idea: Leibniz rejects Hobbes's legal positivism in favour of the older natural law theory associated with Aquinas (which says nothing can be a law unless it derives from natural justice). The older view was revived at Nuremberg, to prosecute Nazis.
                        From: report of Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Ch.7
                        A reaction: This seems to suggest that Hobbes and co were using Ockham's Razor to eliminate morality from the law, but that the Nuremberg situation (and modern trials in The Hague) show that there is a necessity for natural law in international situations.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
Leibniz rejected atoms, because they must be elastic, and hence have parts
                        Full Idea: Leibniz held that there can be no atoms in nature, nothing perfectly solid and hard, since elasticity entails the existence of smaller parts that can move with respect to one another.
                        From: report of Gottfried Leibniz (works [1690]) by Daniel Garber - Leibniz:Body,Substance,Monad 5
                        A reaction: Thus, I suppose, we discover that atoms have mercurial electron shells. Are quarks or electrons elastic? The debate about true atoms is not over, and probably never will be. Leibniz's point is a good one.
Microscopes and the continuum suggest that matter is endlessly divisible
                        Full Idea: Micrographers observe qualities of larger things found in smaller things. And if this proceeds to infinity - which is possible since the continuum is divisible to infinity - any atom will be an infinite species, and there will be worlds within worlds.
                        From: Gottfried Leibniz (works [1690], A VI ii 241)
                        A reaction: [a work of the 1670s] The microscope had a huge impact on Leibniz, much more than the telescope.
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / a. Early Modern matter
Leibniz struggled to reconcile bodies with a reality of purely soul-like entities
                        Full Idea: Leibniz seems never to have made up his mind completely on how to accommodate bodies within a metaphysic which recognises only soul-like entities as fully real.
                        From: comment on Gottfried Leibniz (works [1690]) by Nicholas Jolley - Leibniz Intro
                        A reaction: [The soul-like entities are his 'monads']. His choice must be to either say they are unreal, or that they are real and separate from the monads, or that they are a manifestation of the monads. His problem, not mine.
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / c. Matter as extension
Leibniz eventually said resistance, rather than extension, was the essence of body
                        Full Idea: Leibniz eventually rejected extension altogether as part of the essence of body, and replaced it with resistance.
                        From: report of Gottfried Leibniz (works [1690]) by Robert Pasnau - Metaphysical Themes 1274-1671 15.5
                        A reaction: This makes body consist of active force, rather than mere geometry. Much better.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
Leibniz wanted to explain motion and its laws by the nature of body
                        Full Idea: Leibniz seeks the big picture: the nature of body as a grounding for an account of motion and its laws.
                        From: report of Gottfried Leibniz (works [1690]) by Daniel Garber - Leibniz:Body,Substance,Monad 4
                        A reaction: Garber is contrasting this with Newton's approaches, who just pleads ignorance of the bigger picture. Essentialists must beware of inventing a bigger picture simply because they desperately want a bigger picture.
The law within something fixes its persistence, and accords with general laws of nature
                        Full Idea: Nothing is permanent in a substance except the law itself which determines the continuous succession of its states and accords within the individual substance with the laws of nature that govern the whole world.
                        From: Gottfried Leibniz (works [1690], G II:263), quoted by David Wiggins - Sameness and Substance 3 epig
                        A reaction: An interesting link between the law-of-series within a substance, and the broader concept of laws outside it.
26. Natural Theory / D. Laws of Nature / 10. Closure of Physics
Leibniz had an unusual commitment to the causal completeness of physics
                        Full Idea: Unlike most philosophers prior to the twentieth century, Leibniz was committed to the causal completeness of physics.
                        From: report of Gottfried Leibniz (works [1690]) by David Papineau - Thinking about Consciousness 1.4
                        A reaction: It has been suggested that Leibniz was actually, in private, a determinist (see Idea 7841), which would fit. Leibniz is enigmatic, but he may have proposed the closure of physics to glorify God, only to find that God was beginning to look irrelevant.
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
Leibniz uses 'force' to mean both activity and potential
                        Full Idea: At this early period exegetical problems abound, since Leibniz uses 'force' both for actually acting forces and for potentials or powers.
                        From: Gottfried Leibniz (works [1690], 9.II), quoted by Harré,R./Madden,E.H. - Causal Powers 9.II.B
                        A reaction: I take Leibniz to be a key figure in the development of the Aristotelian approach, because he connected Aristotelian potential and essence with 'force' in the new physics. This is helpful in reading him correctly.
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
God's existence is either necessary or impossible
                        Full Idea: Leibniz said that the ontological argument does not prove God's existence, but only the God's existence is either necessary or impossible.
                        From: report of Gottfried Leibniz (works [1690]) by Roger Scruton - Modern Philosophy:introduction and survey 13.5
28. God / C. Attitudes to God / 5. Atheism
Leibniz was closer than Spinoza to atheism
                        Full Idea: Leibniz sailed closer to the winds of unbelief than Spinoza did.
                        From: report of Gottfried Leibniz (works [1690]) by Matthew Stewart - The Courtier and the Heretic Ch.16
                        A reaction: This is an unusual view, but Stewart's view is that whereas Spinoza is always sincere in his writings, Leibniz is inclined to put a very conservative spin on his opinions. A key question for Leibniz is "Is God merely a monad?"